I have a set of coolers on Sickly. I like the clear covers with stainless steel guards, but decided to make a set of covers from 1/4" aluminum. I'm just worried about the hunting trips, trails, rocks etc. that might bounce up. OTOH, those plastic covers are pretty thick--it'd take a good hit to crack one. Since I got mine before the magnetic plugs were available, I bolted a magnet to the inside of the driver's side aluminum cover.
AFAIK, no one yet has mantioned that these coolers make the trans more stable on the transmission jack while replacing the clutch! A nice extra benefit. If any of you had the transmission rotate due to the offset weight of the transfer case, you know what I mean. Mine ended up hanging by that Chinese strap I got for $3 at harbor Freight as a safety strap. Not an experience I would like to repeat, and with the Fast Coolers, shouldn't have to.